Bioactivity Of19Plant Essential Oils Against Myllocerinus Aurolineatus And Polyphenol Oxidase Genes Cloning Of Camellia Sinensis

In order to find new non-polluting control methods for the tea weevil Myllocerinus aurolineatus Voss, a behavioral bioassay was conducted to test the repellent activity of nineteen plant essential oils on this pest. The results show that allitridi, lavender oil, baicalin, extract of Cantleyt corniculata (Becc) Howard, Salvia miltiorrhiza Bunge, Andrographis paniculata (Burm.f.) Nees, Artemisia argyi Levl. Et Vant, Fallopia multiflora (Thunb.) Harald, Sophora flavescensn Alt., Leonurus artemisia Sweet and Lonicera Japonica Thunb., were repellent to both male and female M. aurolineatus adults. Of these, allitridi,S. miltiorrhiza extract, F. multiflora extract, and extract of S. flavescensn reduced feeding by adult weevils relative to the control. Extract of C. corniculata and L. Japonica reduced feeding activity, whereas allitridi and extract of L. artemisia significantly enhanced the appetite of adult weevils relative to the control. Artemisia argyi extract, lavender oil, and baicalin, although repellent, did not reduce feeding activity relative to the control. Compared with the control, extract of A. paniculata was attractive to weevils. Further research on the effects of extracts of C. corniculata, S. miltiorrhiza, F. multiflora, S. flavescensn, and L. Japonica on tea weevils is required to fully determine the control potential of these compounds.It has been reported that plant insect resistance is often strongly polyphenol oxidase (PPO) dependent. Molecular technologies,3’-RACE, DNA walking and5’-RACE were used in this study, a new PPO gene from tea (Camellia sinensis) was sequenced and its full sequence is1740bp. Through phylogenetic analysis, we found that the genetic relationship of two tea PPOs (PPO1and PPO2) is far and belong to two different sublines. Tea PPO1branched individually and tea PPO2was closed to Ptd PPO2(GenBank accession number: AAU12256) and Ptd PPO3(GenBank accession number:AAU12257) in hybrid poplar (Populus trichocarpa×Populus deltoides). In addition, expression levels of two tea PPOs genes in different parts of tea plant were analyzed by RT-PCR. The results indicated that PPO1has a relative high expression level in roots but a lower level in young leaves, old leaves, young stems and old stems; on the contrary, PPO2has a relative high expression level in young stems of tea but a lower level in young leaves, old leaves, old stems and roots. Different expression level of these two genes indicated that genes in PPO gene family may have different functions in different tissues or different developmental stages of same tissue. The results may offer scientific foundation for future research.